Arcing current, such as a lightning strike, can attach to conductive objects near or contained within non-conductive enclosures. For example, lightning has penetrated nose radomes on aircraft and forced lightning currents in excess of 200,000 amperes into the antennas and other sensitive electronics underneath the nose radomes. Such lightning strikes cause considerable degradation of the radome structure and extensive damage to the underlying antenna and sensitive electronics.
Lightning diverter strips have been devised in the past to prevent lightning puncture of radomes. These lightning diverter strips provide an alternate electrically conductive path for the lightning current. Typically, the lightning diverter strip is applied over the outer surface of the radome with one end of each lightning diverter strip electrically grounded to the conductive airplane structure.
There are three main forms of lightning diverter strips. One form is the continuous metal conductor, which includes metal bars and foils. Another form is the segmented diverter strip which is comprised of closely spaced metal segments that have been applied to a flexible strip material. The third form of lightning diverter strip applies finely powdered aluminum to a non-conductive substrate using a flexible epoxy such that the strip will have a very high DC resistance but will conduct lightning current.
The three main conventional diverter strip forms have one or more of the following disadvantages. The lightning diverter strip may have a detrimental impact on the underlying antenna's radio frequency performance. The lightning diverter strip may be damaged during a lightning strike, thereby reducing its lightning strike diversion ability for subsequent lightning strikes. The lightning diverter strip may be susceptible to weather erosion which reduces the lightning diversion effectiveness of the strip, or the lightning diverter strip may be visible on the radome surface which detracts from the aesthetics of the radome.